JEKYLL ISLAND | The Jekyll Island Authority board adopted a draft master plan Monday that increased the island’s size by 1,340 acres since the 1996 master plan that will likely set off a public relations battle with conservationists.

The authority also adopted a firm number of acres for development - 1,675 acres - which is a departure from the old method of simply remaining under the 35 percent limit imposed by law.

That leaves 66 acres for development, 46 acres that could be used only for public safety, utilities and recreation and 20 acres that could be used as the board deems appropriate.

The draft must undergo a public hearing before final adoption as the master plan and the change in setting development limits would require a change in state law.

Of the island’s 5,540 acres, 1,609 are already considered developed whether it be with buildings, golf courses or dirt roads.

The authority board has said it wants the General Assembly to adopt legislation adopting that firm acreage. Current law limits development to no more than 35 percent of the island’s land, but that is controversial because the authority and conservationists disagree on the island’s actual size.

The sticking point with conservationists remains an interpretation of a state law that establishes Jekyll Island’s size. David Egan of the Initiative to Protect Jekyll Island said that the authority is wrongly following an interpretation of state law that Attorney General Sam Olens approved. Olens said that the island’s size can be determined with a survey of all the land above the mean, or average, high tide mark.

Egan and others said that the law dating to the 1970s refers to land “above water at mean high tide,” not the land above the tide mark itself.

By using the mean high tide mark, as established by the National Oceanic and Atmospheric Administration, the authority is taking in a lot of marsh, Egan said.

Egan notes that a lot of the marsh that is flooded during an average high tide is on the proposed master plan map as land.

“If it’s below water, it doesn’t count,’’ he said.

Should that map be adopted, which he asserts is clearly wrong, the public would have to live with it for 20 years until the next master plan, Egan said.

“Somebody has to make it clear to these guys you can’t adopt a map like that that’s going to be around 20 years,’’ Egan said. “Somebody has to recognize that the marsh is a wet environment.’’

Dave Kyler, executive director of the Center for Sustainable Coast, called the map bogus.

“You can see the water on their map,’’ Kyler said indicating an area on the northwestern side of the island that has a network of tidal creeks and that is often flooded.

Egan said that a video will be made of the marsh that the authority says is land. That video will be aired publicly, he said.

There are a couple more meetings scheduled before the authority meets to formally adopt the master plan Nov. 18.